Jokes that are considered stupid often make people laugh by making very little sense or using obvious puns. When telling such jokes, people often ask a question first, give the audience a few moments and deliver the punch line.
"Is there a hole in your shoe?" asks the joker, expecting a negative answer. After all, what he has in mind is not what the average guy considers a hole in a shoe. Receiving negative response, "then" asks the joker, "how did you get your foot into it?" Technically speaking, all shoes have holes that people put their feet through, but no one considers them holes.
The joker asks "What did the pirate say on his 80th birthday?" Gives the audience a few moments to ponder on the question, and delivers the punch line "Aye Matey!" The joke is that "aye matey" sounds really similar to "I'm eighty."
"What kind of bagel can fly?" asks the joker. The audience makes all sorts of guesses, hopefully missing the answer: a plain bagel. The word plain has the exact same pronunciation as the word plane, hence the joke.
The joker starts by saying that he remembers the last thing his grandfather said to him before he kicked the bucket. The joker waits for a few seconds and delivers the joke "Hey, how far do you think I can kick this bucket?" Kicking the bucket is an idiom for death. However, the grandfather literally kicks a bucket in the joke.